Comparison of the original CRIRES (blue) and CRIRES⁺ (red) measured electrons per second per pixel as a function of wavelength in the JHKLM bands. Multiple blue or red lines in the subpanels refer to distinct observations of the same target when the observing conditions were different. Spectra were not corrected for slit losses. The AO performance of CRIRES⁺ is typically the same or better than the original instrument. The CRIRES⁺ data have been multiplied by 1.5 to account for the smaller pixel size for the new H2RG detectors (18 μm) to Aladdin InSb detectors pixels (27 μm) of the original CRIRES. Spectra were not corrected for either atmospheric telluric absorption or radial velocity shifts due to the Earth’s motion. Wavelengths were taken from the FITS headers.